Railway signaling system.



WITNESSES:

off 70 PATENTED FEB. 25, 1903.

W W. SALMON.

RAILWAY SIGNALING SYSTEM.

APPLIOATION FILED JULYE]. 1907.

INVENTORL Z% UNlTED STATES PATENT orrros;

WILMER W. SALMON, OF ROCHESTER, NEW YORK, ASSIGNOR TO cENEii-A'ii RAILWAY SIGNAL COMPANY, OF GATES, xsw YORK, A CORPORATION 'OF NEWYORK.

RAILWAY SIGNALING srs'rsm.

' Specification of Letters Patent.

Application filed July 3- 1907- Serial No. 382.123-

Patented FLJ. 25, 1908.

' Signaling Systems, of which the following is a specification.

This invention relates to railway signaling systems, and particularly to means for adding new features of safety to signaling apparatus already known.

-The invention consists. in

the apparatus hereinafter described and claimed.

- In adapting a system of signals to electric railways, it has been found desirable to employ electric currents having different properties or characteristics, for the propulsion and for the signaling. As an example of )tiii'ese different currents, direct current will be describedfor the propulsion, and alter-' nating current for. the si aling. The example of signal exhibited will be a semaphore arm.

The railway track has two rails, of which rail 1 in the diagrammatic drawing will be called the. propulsion rail herein, and is employed for the return of the direct or ropulsion current, while the rail 2 is 0 ed the signaling rail herein, and is employed for conductlng the; alternating or signal current only. A signaling circuit is emp oyed which includes signahng devices and includes a portion of the propulsion rail.

Ordinarily, for signaling purposes, the signal ing rail is divided into a series of insulated sections A, B, C, each-of which has relation to the operation of a particular'signal or tions of the signaling rail.

semaphore, and is a part of the signaling circuit pertaining thereto.

In the said drawing, 3, 3 are the insulating joints for separating, electrically, the seca, 5 are the wires of the si naling feed systerm, which are connected with the alternat mg current dynamo 6. For each signaling section there is a transformer], having its primary 8 connected in multiple with the signaling feed system, and its secondary 9 connected with the rails 1 and 2. The resistance 10 is inserted in the connection to.

the propulsion rail 1 of the said secondary, in order to cut down direct current which 7 passinto the'transformer. An'altersignaling sections A,

purpose as the resistance 10. The relay has an armature .15 in the local motor circuit of the signal. Vv'hen the armature is attracted, the local motor circuit is closed, and the motor operates to actuate the semaphore arm and to hold it at safety, as at 18 and 19; while if the relay armature is not attracted, it falls away from its contact, the said local motor circuit Opens, and the semaphore arm is no longer heldat safety, but automatically moves to the danger position by the action of its counterweight 2O as shown at 17. The propulsion feed wire 21 is connected with a direct current dynamo 22, which is also connected to the propulsion rail 1.

When a car enters ilipon anly one of the C, s own in the diagrammatic plan, current from the transformer 7 passes through the Wheels and axles of the car, and not through the secondary 13 of the relay 11, whereupon current through the relay ceases, the armature drops, the circuit 16 opens, and the semaphore arm moves to the danger position.

It has been customary to provide an addi- "tional or supplemental return conductor 23 for the direct current, and to connect it by a suitable number of cross-bonds 24, 25, with the propulsion rail, so that there shall be a certainty of free and ample return for the propulsion current after assing through the motor ofthe car. Wit the construction thus fardescribed, the presence of a car on any of the signaling sections; is exhibited as described. In case the signaling rail should be broken, the current to the relay would be cut off, and the semaphore relating. to the section in which the break exists, would im- But if a break 7 mediately go to danger. should occur inthe propulsion rail, a circuit is formed through the cross-bonds and return conductor, so. that the current from the transformer 7 would pass through the relay, and the break of the propulsion rail W0 1 d not be signaled.

sion rail in electric railway systems in w ch an additional return conductor has been cross-bonded with the propulsion-rail and it 1.0 is to the removal of this dan erous defect that the, present invention is'idirected. For

thispurpose, the propulsion railis divided into-a-series of sections, suchas E, F, by means of insulating'joints 28, 29, 30, and, ,two

cross-bonds areprovided extending fromathe return conductor 23, one to one end of an insulated section of the propulsion rail, such as F, and theother to the otherend of the same section. One end of the section has a simple cross-bond, orconnection, such as 24;v The otherend' of'the same section -(F) has acrossbond or connection 26in serieswith'a react- 'ance 31,of such character that with the particular alternating current employed, the. said current will bestopped or choked to an extent sufficient to denergize the relay 110i, the section in question; and thus a circuit for the passage of alternating current through the relay-of section F cannot'be made either, 30 through a break in a section of the propuls sion rail or around the break through the cross-bonds andreturn conductor.

A reactance'is a device that, under determined conditions, separates, either vcom-.

pletely or partially,- two currents flowing in the same conductor. 1 In the present instance, of the invention, the reactance described is "the "well known reactance which chokes or.

stops-the passage of an alternating current but which permits the passage of a direct current. Itis,.of course, possible, and will cause a saving in wiring and construction in some cases, to connect the reactance on one "side of. an insulated joint with the crossbond on the other side of said joint, and to employa-common connection to the return cbnductor' 235501 the cross-bond and the reactance. 'Thisconnection is shown inthe diagram by connectin the reactance 33 and the cross-bond 25, so t atthegreater part of the cross-bond 25 is. employed as a common conneotion'to the return conductor for both. The same construction is produced by bridging the insulated joint 29 by the reactance 32, sothatthe cross-bond 24 and a portion 'of the rail section F are em loyed as the common connection orcro'ss- 0nd in series with saidreactance.

'By the use of two cross-bond'connectio'ns with the return "conductor from'each insiif I lated section of the propulsion rail, either of which affords a sufliciently free path to the propulsionjcurrent, and one of which con- .tains a reactanceand checks the "signaling i 4 current, the employment of a small reactance is possible, be explaine'd.- lh'e cross bonds are connected to the insulated sec- One terminal of the secondary 9 of the trans:

former 7" is likewise connected near to one end of an insulated section of the propulsion rail, and the other terminal near to the end of the, adjacent insulated section of the signaling raily and the terminals of the 'secon 'aryr1'3 of the relay are connected near to the otherv'ends of the same insulatedsections.

' With the arrangement shown, in which the return conductor has two cross connections for each insulated section of the propulslon rail, one cross-connection to one end of said section and the other cross-section to the. other end of said section, and a reactance 1n series with one of said cross-connections, the

signal will" go to-danger immediately upon a 'is' in the position shownin dotted lines, the .11

break in,the propulsion rail between said 35 cross-connections thereto and when no. car 1s on the broken insulated section. For th1s reason thecar 1s not a necessary element of this invention, and the entry of acar' upon the same broken insulated section of the pro pulsion rail will not set the signal to safety. When the car is on the section Fin the full line position, and abreak has oocurred in the propulsion rail at the point marked X,

propulsion current asses throu h the crossbond 26, and the w ole return om the car motor must pass throu h the cross-bond 24. The signaling current, om the transformer 7 "is shunted bythe wheels and axlesof the car, so that no current will pass around 0 through the cross-bond 24; return conductor 23, and cross-bond 26 to energize the relay attached tothe signaling section 0. If any signaling current should esca e by reason of imperfect shunting by the w eels and aides of th'e'car, it would be'choked by the react ance 31 so far as to prevent energizatio'n'of the relay. If a breakhas occurred in the section F at the point marked X, and thecar entire return bf the pro ulsi'on current occurs through the cross-hon 26 and the reactance 31, but signaling current, even if it could ass the reactance 31, is shunted from the re ay,

so that thecurrent from the transformcr'115- passes through the cross-bond 24, return conductor 23,f'cross-bond 26, reactance 31, propulsion rail section F, wheels and axlesin the dotted line position, signaling section 0,

and to the transformer.- If the propulsion current passing through the reactance 1s. suflicientto saturate the core thereof, the

: said reactance'will cease to act as a reactance,

and, underthese circumstances, the shunt 7 just mentioned would besufficientto prevent current from passing'to the relay 11; but if the propulsion. current is not sufficient to saturate the 'reactance (and the reactance should be so constructed as not to be saturated), then the reactance chokes or prevents 13o A and B of the signaling rail.

bond should be connected to the same end of the insulated section of the propulsion rail to which the relay is connected. In the specific arrangement shown, the reactance can be made small, because when itis necessary for it to act as a reactance, no propulsion current passes through it, and when it is not acting as a reactance, it does not matter whether it is saturated or not. It will be noted that the section E of the propulsion rail has adjacent to it two insulated sections If a break in the propulsion rail should occur at Y between the terminal connections to the pro ul-r sion rail of the transformer and of the re ay,

' conductor or throug the signal 18 will go to danger, and the signaling current cannot ass through the return h the cross-bonds of the section E, but the signal 19 will not be affected by the break at Y. A break at Z will set the signal 19 to danger, but will not affect the signal 18. 7

Insulated joints in the trafiic-rail need be placed only at those points where cross-bonds are placed. It will be clear from the above description that a signal circuit may include either the whole or a part of aninsulated section of the traffic rail.

It will be clear that in this invention a break at any point in the propulsion rail between two cross connections prevents passage of propulsion current through the reactancein one of said cross connections, because the break and an insulated joint preclude the access of propulsion current thereto.

' What I claim is r t 1. In a si naling system for electric railways, a trac in which one rail is the return conductor for the propulsion'current a supplemental return conductor for the propulsion current; cross connections between the propulsion rail and the supplemental return conductor a signaling circuit which includes a portion of the propulsion rail; signaling devices in said signaling circuit adapted to be energized by a current of different properties from the propulsion current and means for preventing the operation of the signaling 1 devices while a break exists in said portion of ways, a trac the propulsion rail.

2. In a si 'naling system for electric railin-which one rail is the return conductor for the propulsion current; a supplemental return conductor for the propulsion current; cross connect-ions between the propulsion rail and the supplemental return conductor a signalin circuit which includes a portion of the propulsion rail; signaling devices in said signaling circuit adapted tobe energized by a current of different properties from the limiting t through the cross connections while a break exists in said portion of the propulsion rail.

3. In a signaling system for electric-rail ways a track in which one rail is the return conductor for the propulsion current, a sup.-

protpulsion' current; and means for e ow of signahng current flowing plemental return conductor for the propul-rzsion current; cross connectionsbetween the propulsion rail and the supplementalreturn conductor; a signaling circuit which includes a portion of the propulsion rail between;

adjacent cross -connections; signaling (16-- vices in said signaling circuit adapted to be energized by a current of different properties from the ropulsion current; a reactance in series with one of said adjacent cross con nections; and means for preventing access of the propulsion current to said reactance while a break exists in said portion of the propulsion-rail.

4. In a signaling system for electric railways, a track in which one rail is the return conductor for the ropulsion current and is divided into insu ated sections; a supplemental return conductor for the propulsion current; cross'connections between the ends of an insulated section of the propulsion rail and the supplemental return conductor; a signaling circuit which includes the whole or a part of said section of the propulsion rail; signaling devices in said signaling circuit adapted to be energized by a current of different properties from the propulsion current; and a reactance in series with one of said crossconnections.

5. In a signaling system for electric railways, a track in which one'rail is the return conductor for the repulsion current and in divided into insu ated sections; a supplemental return conductor for the pro ulsion current; cross-connections between't e' ends of an insulated section of the propulsion rail and the supplemental return conductor; a

6. In a-two-rail electric railway system, in i which one rail is the propulsion rail and is divided into insulated sections and is used vfor conducting a propulsion current, and

the second rail is the signaling rail and is divided into insulated sections adjacent to I the sections of the propulsion rail and is used for conducting a signaling current of differentproperties from the propulsion current; a feed conductor for the propulsion current; a return conductor for the propulsion current; two cross-bond connections extending said signaling, circuit; t.

'the signaling. current; a signaling circuit from the i'eturn'fconductor to opposite ends of an' insulated-section of the propulsion rail;

areactanee series with one of said crosss .bond connections] constructed to'permit passage of the propulsion current and to choke jincludingthe said insulated section of the si paling-rail and'the whole or a part of the a Jacent insulated section ofthe profuls'ion led by:

rail; and signaling. apparatus contr .17, In a tworail electric railway system} in which one rail is the propul sion'rail andis dividedintoinsulatedsections andis used fortherreturn of-direct' current, and the second rail iswth signaling rail and is used for, conducting "alternating" current; a feed-- wconduptor for the prop llsioncurrent; a re- 1 thru Icond'uctorfor the propulsio'n'current;, a

- sulateld-sectionr of the propulsion rail; a: v reactance in 1 series I With. one of 's'aid" crossfeed system for the alternating current .two' ond connections extendin from the return conductorto opposite en sof an in- -bond'conne' ction's constructed to' permit assage ofdirect current and to chokethe a terhating current;'- a 'signaling circuit including. the said insulated section-of the signaling rail and the wholeor apart of the a j'acen-t insulated section of the propulsion rail a H transformer and an alte'rnati each having a primary "win ing connected.

current relay,

1 with said feed system and 'a secondary wind in said signaling circuit; and" a :local I motoreircuit for iii si n controlled by drela'yj 8. In a two-rail electric railway system, in

which one-rail is the propulsion'rail and is divided into insulatedv sections and isused forthe return of direct current, and the seeondlrail is the signaling rail and is'divided into insulated sections and is used for con- I ducting alternating current; afeed conductor I ffOI the propulsion current; a return conductor for the propulsion current; a feed system .for the alternating current two cross-bond current relay at the other end of saidtwo.

sections, each-having a primary winding connected with said feed system and a secondary winding .in said signaling circuit; and a local motor circuit for a signal controlled by said relay.

V WILM ER SALMON, Witnesses: t

' L; DonesoN,

MYRTL A. H aavrn. 

